// Title: tigra slider control
// Description: See the demo at url
// URL: http://www.softcomplex.com/products/tigra_slider_control/
// Version: 1.0.2 (commented source)
// Date: 08/21/2008
// Tech. Support: http://www.softcomplex.com/forum/
// Notes: This script is free. Visit official site for further details.

function slider (a_init, a_tpl) {

    this.f_setValue  = f_sliderSetValue;
    this.f_getPos    = f_sliderGetPos;
    
    // register in the global collection    
    if (!window.A_SLIDERS)
        window.A_SLIDERS = [];
    this.n_id = window.A_SLIDERS.length;
    window.A_SLIDERS[this.n_id] = this;

    // save config parameters in the slider object
    var s_key;
    if (a_tpl)
        for (s_key in a_tpl)
            this[s_key] = a_tpl[s_key];
    for (s_key in a_init)
        this[s_key] = a_init[s_key];

    this.n_pix2value = this.n_pathLength / (this.n_maxValue - this.n_minValue);
    if (this.n_value == null)
        this.n_value = this.n_minValue;

    // generate the control's HTML
    document.write(
        '<div style="width:' + this.n_controlWidth + 'px;height:' + this.n_controlHeight + 'px;border:0; background-image:url(' + this.s_imgControl + ')" id="sl' + this.n_id + 'base">' +
        '<img src="' + this.s_imgSlider + '" width="' + this.n_sliderWidth + '" height="' + this.n_sliderHeight + '" border="0" style="position:relative;left:' + this.n_pathLeft + 'px;top:' + this.n_pathTop + 'px;z-index:' + this.n_zIndex + ';cursor:pointer;visibility:hidden;" name="sl' + this.n_id + 'slider" id="sl' + this.n_id + 'slider" onmousedown="return f_sliderMouseDown(' + this.n_id + ')"/></div>'
    );
    this.e_base   = get_element('sl' + this.n_id + 'base');
    this.e_slider = get_element('sl' + this.n_id + 'slider');
    
    // safely hook document/window events
    if (!window.f_savedMouseMove && document.onmousemove != f_sliderMouseMove) {
        window.f_savedMouseMove = document.onmousemove;
        document.onmousemove = f_sliderMouseMove;
    }
    if (!window.f_savedMouseUp && document.onmouseup != f_sliderMouseUp) {
        window.f_savedMouseUp = document.onmouseup;
        document.onmouseup = f_sliderMouseUp;
    }
    // preset to the value in the input box if available
    var e_input = this.s_form == null
        ? get_element(this.s_name)
        : document.forms[this.s_form]
            ? document.forms[this.s_form].elements[this.s_name]
            : null;
    this.f_setValue(e_input && e_input.value != '' ? e_input.value : null, 1);
    this.e_slider.style.visibility = 'visible';
}

function f_sliderSetValue (n_value, b_noInputCheck) {
    if (n_value == null)
        n_value = this.n_value == null ? this.n_minValue : this.n_value;
    if (isNaN(n_value))
        return false;
    // round to closest multiple if step is specified
    if (this.n_step)
        n_value = Math.round((n_value - this.n_minValue) / this.n_step) * this.n_step + this.n_minValue;
    // smooth out the result
    if (n_value % 1)
        n_value = Math.round(n_value * 1e5) / 1e5;

    if (n_value < this.n_minValue)
        n_value = this.n_minValue;
    if (n_value > this.n_maxValue)
        n_value = this.n_maxValue;

    this.n_value = n_value;

    // move the slider
    if (this.b_vertical)
        this.e_slider.style.top  = (this.n_pathTop + this.n_pathLength - Math.round((n_value - this.n_minValue) * this.n_pix2value)) + 'px';
    else
        this.e_slider.style.left = (this.n_pathLeft + Math.round((n_value - this.n_minValue) * this.n_pix2value)) + 'px';

    // save new value
    var e_input;
    if (this.s_form == null) {
        e_input = get_element(this.s_name);
        if (!e_input)
            return b_noInputCheck ? null : f_sliderError(this.n_id, "Can not find the input with ID='" + this.s_name + "'.");
    }
    else {
        var e_form = document.forms[this.s_form];
        if (!e_form)
            return b_noInputCheck ? null : f_sliderError(this.n_id, "Can not find the form with NAME='" + this.s_form + "'.");
        e_input = e_form.elements[this.s_name];
        if (!e_input)
            return b_noInputCheck ? null : f_sliderError(this.n_id, "Can not find the input with NAME='" + this.s_name + "'.");
    }
    e_input.value = n_value;
}

// get absolute position of the element in the document
function f_sliderGetPos (b_vertical, b_base) {
    var n_pos = 0,
        s_coord = (b_vertical ? 'Top' : 'Left');
    var o_elem = o_elem2 = b_base ? this.e_base : this.e_slider;
    
    while (o_elem) {
        n_pos += o_elem["offset" + s_coord];
        o_elem = o_elem.offsetParent;
    }
    o_elem = o_elem2;

    var n_offset;
    while (o_elem.tagName != "BODY") {
        n_offset = o_elem["scroll" + s_coord];
        if (n_offset)
            n_pos -= o_elem["scroll" + s_coord];
        o_elem = o_elem.parentNode;
    }
    return n_pos;
}

function f_sliderMouseDown (n_id) {
    window.n_activeSliderId = n_id;
    return false;
}

function f_sliderMouseUp (e_event, b_watching) {
    if (window.n_activeSliderId != null) {
        var o_slider = window.A_SLIDERS[window.n_activeSliderId];
        o_slider.f_setValue(o_slider.n_minValue + (o_slider.b_vertical
            ? (o_slider.n_pathLength - parseInt(o_slider.e_slider.style.top) + o_slider.n_pathTop)
            : (parseInt(o_slider.e_slider.style.left) - o_slider.n_pathLeft)) / o_slider.n_pix2value);
        if (b_watching) return;
        window.n_activeSliderId = null;
    }
    if (window.f_savedMouseUp)
        return window.f_savedMouseUp(e_event);
}

function f_sliderMouseMove (e_event) {

    if (!e_event && window.event) e_event = window.event;

    // save mouse coordinates
    if (e_event) {
        window.n_mouseX = e_event.clientX + f_scrollLeft();
        window.n_mouseY = e_event.clientY + f_scrollTop();
    }

    // check if in drag mode
    if (window.n_activeSliderId != null) {
        var o_slider = window.A_SLIDERS[window.n_activeSliderId];

        var n_pxOffset;
        if (o_slider.b_vertical) {
            var n_sliderTop = window.n_mouseY - o_slider.n_sliderHeight / 2 - o_slider.f_getPos(1, 1) - 3;
            // limit the slider movement
            if (n_sliderTop < o_slider.n_pathTop)
                n_sliderTop = o_slider.n_pathTop;
            var n_pxMax = o_slider.n_pathTop + o_slider.n_pathLength;
            if (n_sliderTop > n_pxMax)
                n_sliderTop = n_pxMax;
            o_slider.e_slider.style.top = n_sliderTop + 'px';
            n_pxOffset = o_slider.n_pathLength - n_sliderTop + o_slider.n_pathTop;
        }
        else {
            var n_sliderLeft = window.n_mouseX - o_slider.n_sliderWidth / 2 - o_slider.f_getPos(0, 1) - 3;
            // limit the slider movement
            if (n_sliderLeft < o_slider.n_pathLeft)
                n_sliderLeft = o_slider.n_pathLeft;
            var n_pxMax = o_slider.n_pathLeft + o_slider.n_pathLength;
            if (n_sliderLeft > n_pxMax)
                n_sliderLeft = n_pxMax;
            o_slider.e_slider.style.left = n_sliderLeft + 'px';
            n_pxOffset = n_sliderLeft - o_slider.n_pathLeft;
        }
        if (o_slider.b_watch)
             f_sliderMouseUp(e_event, 1);

        return false;
    }
    
    if (window.f_savedMouseMove)
        return window.f_savedMouseMove(e_event);
}

// get the scroller positions of the page
function f_scrollLeft() {
    return f_filterResults (
        window.pageXOffset ? window.pageXOffset : 0,
        document.documentElement ? document.documentElement.scrollLeft : 0,
        document.body ? document.body.scrollLeft : 0
    );
}
function f_scrollTop() {
    return f_filterResults (
        window.pageYOffset ? window.pageYOffset : 0,
        document.documentElement ? document.documentElement.scrollTop : 0,
        document.body ? document.body.scrollTop : 0
    );
}
function f_filterResults(n_win, n_docel, n_body) {
    var n_result = n_win ? n_win : 0;
    if (n_docel && (!n_result || (n_result > n_docel)))
        n_result = n_docel;
    return n_body && (!n_result || (n_result > n_body)) ? n_body : n_result;
}

function f_sliderError (n_id, s_message) {
    alert("Slider #" + n_id + " Error:\n" + s_message);
    window.n_activeSliderId = null;
}

get_element = document.all ?
    function (s_id) { return document.all[s_id] } :
    function (s_id) { return document.getElementById(s_id) };

